Just install 12.04-64bit and while I can login using the guest login, I cannot with my user login: it just cycles back to the login screen. I have performed the sequence of apt-get update/upgrade and install of the nvidia-current driver, but got back that it was already in use. The password appears to be recognized, as wrong one results in an error. Have also tried switching to the 2D Unity, without other results.

Initially from my clean install of 12.04 (64bit), the login screen would intermittently repeat, and the second time the login would be stuck with "Logging in..." under the user name.

Found a bug report about the "Logging in..." stating that this was caused by using a non-default wallpaper and an issue with lightdm. I have reverted to a plain blue background, and I now no longer get the "Logging in..." freeze issue - however, I consistently get two login screens!

I enter credentials correctly and am immediately presented with a second login screen (no errors). Authenticating against the second screen completes a normal login to the Ubuntu desktop.

Any ideas what is going on here? I don't see any obvious errors in the logs (maybe I am looking in the wrong logs).

This is potentially the same issue. Has this been resolved by recent updates?
–
david6May 18 '12 at 9:11

there are a lot of questions (and answers) regarding problems with the login screen. Please check them first (use the search box at top) and include which solutions didn't work for you. If it's a new issue that wasn't asked before, you should create a new question instead of adding it as an answer to an older question - thw current way, you're decreasing the probability that your question will be recognised by a larger count of users dramatically.
–
tohuwawohuMay 18 '12 at 9:13